100428121 has 2 divisors, whose sum is σ = 100428122. Its totient is φ = 100428120.

The previous prime is 100428103. The next prime is 100428169. The reversal of 100428121 is 121824001.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 73273600 + 27154521 = 8560^2 + 5211^2 .

It is a cyclic number.

It is not a de Polignac number, because 100428121 - 2¹⁹ = 99903833 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (100423121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 50214060 + 50214061.

It is an arithmetic number, because the mean of its divisors is an integer number (50214061).

Almost surely, 2^100428121 is an apocalyptic number.

It is an amenable number.

100428121 is a deficient number, since it is larger than the sum of its proper divisors (1).

100428121 is an equidigital number, since it uses as much as digits as its factorization.

100428121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 128, while the sum is 19.

The square root of 100428121 is about 10021.3831879636. The cubic root of 100428121 is about 464.8203275479.

The spelling of 100428121 in words is "one hundred million, four hundred twenty-eight thousand, one hundred twenty-one".